Improved air-heating apparatus for engine-furnaces



J. H. SHOTWELL.

AIR HEATING APPARATUS FOR ENGINE FURNACES.

Patented N0v.'26, 1861.

E m A fiesses A A [7276725771 A W a, I 1 L UNITED STATES PATENT OFFICE.

JOHN H. SHOTWELL, OF RAHWAY, NEW JERSEY.

IMPROVED AIR-HEATING APPARATUS FOR ENGINE-FURNACES.

To all whom, it hwy concern.-

Be it known that I, JOHN H. SHOTWELL, of Rahway, in the county of Union and State of New Jersey, have invented a certain new and useful Improvement in Heating Apparatus; and I do hereby declare the following to be a full, clear, and exact description of the same, reference being bad to the accompanying drawings, making a part of this specification, in which Figure I is a side elevation of my invention; Fig. 2, a transverse section of the same, taken in the line .2: 0c of Fig. 1; and Fig. 3, a plan of my invention.

1 Similar letters of reference indicate corresponding parts in the several figures.

It is well known that in the ordinary steamengine a very large amount of the heat which is used to convert the water in the boiler into steam is lost after passing through the steamcylinder by being thrown into the atmosphere or condenser.

The object of this invention is to save the greater portion of this heat and return it to the boiler. For this purpose the exhaustpassages of the Steam-cylinder are connected with a heater which is composed of a series of radiators. The exhaust-steam from the cylinder circulating in these radiators throws out its heat and raises the temperature of the air (passing between their radiating surfaces to supply the fire) to ahigh temperature suitable for perfect combustion.

In addition to the apparatus for heating the air and supplying the fire is an apparatus for heating the feed-water for supplying the boiler, as hereinafter to be fully explained.

To enable others skilled in the art to fully understand my invention, I will proceed to describe its construction and operation.

A A are a series of radiators formed of sheets of metal plates united together at their ends, and the adjacent radiating surfaces at top and bottom, so as to form alternate steam and air passages in one of the apparatus and steam and water passages in the other. The steam-passages 1 run vertically or from the top downward, and the air and water passages f g horizontally. A series of protuberances 0, formed on the surfaces of the radiators, prevent them from springing apart by the pressure of the steam. The water-passages at each end are closed by sections of a cylinder B Q, one of which C communicates with the boiler through the pipe D, and the other 13 at the opposite and connects with the doctor or pump for supplying fresh water to the boiler through the pipe N. The steampassages are covered at top by a cap E and at bottom by a box F, fitted to the radiators so as to form a steam-tight joint and secured together by bolts a a.

The exhaust-passage of the steam-cylinder communicates with the steam-passages of the apparatus through the pipe H '-in the upper part of the cap E. The box F communicates with the atmosphere through the pipe I. The small pipe J is placed in the box F below the level of the pipe I, and is for the purpose of letting off the water of condensation. The whole series of radiators are jacketed on two opposite sides, and the air-passages provided at each end with ducts K L.

The operation is as follows: The apparatus is placed near the furnace and the air-passages at one end connected therewith through the duct L, the steam passage 6 with the steam'cylinder through the pipe 11, and the water-passage (1 through the pipe D with the boiler, the pipe N atthe opposite end of the water-passages being connected to a supplypump, as before stated. The exhaust-steam from the steam-cylinder circulating through the radiators causes them to heat the air passing between their surfaces into the furnace to feed the fires to a high temperature, so that when the air meets the burning mass of coals it is in a state suited for perfect combuslion. The steam at the same time circulating in between the water-passages raises the temperature of the water to nearly the boiling-point. As the steam condenses after giving out its heat, itfalls into the box below and passes out of the small pipe J. This pipe may,if desired, have a stop-cock t-o regulate the flow of the water of condensation, and thus prevent steam from passing out therewith.

By using an apparatus of the above-described construction a saving of from twenty (20) to twenty-five (25) per cent. is effected.

\Vhat I claim as new herein, and desire to secure by Letters Patent, is

The combination of the steam-passages with air-passages f and water-passages g, combined, arranged, and operating in the manner and for the purposes set forth.

JOHN H. SHOTWELL. Witnesses:

JAMES H. LIXDLEY, JAMES LAIRD. 

